TO

When a dimensional disturbance brings an alternate Sam and Dean Winchester into the bunker, the Winchesters are forced to confront the differences between their worlds. In the alternate universe, Sam and Dean never had a sister, leaving them fascinated—and quietly saddened—by Y/N’s presence. As the two pairs compare their lives, they discover that family can take many forms, and that even one missing sibling can change everything. But when the instability threatens both universes, the four Winchesters must work together to survive one impossible hunt.